Did the Pandemic Affect Children’s Vision? Research Reveals Rise in Astigmatism

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Children’s eye health changed after COVID-19, with more children developing astigmatism — a condition that causes blurry vision — than before the pandemic, according to research published in JAMA Ophthalmology. Investigators point to alterations in lifestyle caused by the pandemic, including more screen time and less outdoor activity, for the changes in eye development.

Astigmatism, a commonly diagnosed condition among school-aged children, is associated with ametropia. Recent reviews estimate that 14.9% of children worldwide have astigmatism, although this rate varies among those with different ethnicities and geographic locations. For example, in urbanized areas of China, such as Hong Kong, 63.6% of children were reported to have at least 0.5 diopter (D) astigmatism and 21.9% had at least 1.0 D in 2022.

“The COVID-19 pandemic changed the ways people lived, including children,” wrote a team of investigators led by Ka Wai Kam, MSc, associated with the Department of Ophthalmology and Visual Sciences at The Chinese University of Hong Kong. “Schooling became virtual, which was associated with more frequent or prolonged use of electronic gadgets or reduced outdoor time as a result of social restrictions for many children. These changes were associated with a surge in myopia prevalence in children of Hong Kong as well as other parts of the world across the COVID-19 pandemic.”

A cross-sectional study investigated the link between the COVID-19 pandemic and child astigmatism and the prevalence of refractive and corneal astigmatism among a cohort of more than 21,000 children aged 6 to 8 years living in Hong Kong between 2015 and 2023.

The children, who were recruited into the Hong Kong Children Eye Study (HKCES), underwent comprehensive eye examinations at two academic medical centers, and astigmatism was assessed using optical biometry and auto-refractor after cycloplegia. Parents were required to fill out questionnaires on lifestyle and environmental risk factors at the Chinese University of Hong Kong Eye Centre and the Chinese University Medical Centre.

Among the group of children, the mean age was 7.31 years, 52.9% were boys, and 47.1% were girls. In 2015, the prevalence of refractive astigmatism of at least 1.0 D was 21.4%, and the prevalence of corneal astigmatism of at least 1.0 D was 59.8%. These rates increased significantly in 2022 and 2023, to 34.7% and 64.7%, respectively.

Results also showed significant increases in the severity of refractive and corneal astigmatism compared with the 2015 to 2019 period. The rise in cases was not related to whether a child had nearsightedness (myopia), a family history of astigmatism or sociodemographic differences.

The pandemic was linked to a 20% increase in the risk of refractive astigmatism and a 26% increase in the risk of corneal astigmatism.

Investigators noted limitations including generalizability issues, as most of the children were Han Chinese. Additionally, it is likely that different counties and regions may have implemented their own rules on social restrictions. Therefore, the findings seen in this study may not be reproducible in countries that used other quarantine measures. The sample size of participants in 2022 and 2023 was smaller than in the previous years, which could have impacted the accuracy of data. Lastly, it is possible that parental astigmatism was subject to recall bias as it was accounted for using a self-reported questionnaire.

“Given the high prevalence of astigmatism, the potential impact of higher degrees of astigmatism may warrant dedicated efforts to elucidate the relationship between environmental and/or lifestyle factors, as well as the pathophysiology of astigmatism, in order to preserve children’s eyesight and quality of life,” investigators concluded.